That's the number shipped to retailers, not customers. Still, Microsoft exceeded by some unknown number the 5 million units they expected to sell to actual users. The early sales success of Kinect only hints at the monster hit they have on their hands as the capabilities and potential of the Kinect platform become clear.

Kinect is quickly turning into Microsoft's "iPhone" -- the small product that could grow into a monster, change the world and transform the fortunes and direction of the company that makes it.

The Apple iPhone was theoretically a mobile telephone. Instead, it turned out to be so much more: An interface revolution, a new application paradigm and platform and Apple's probably successful attempt to invent the future. The iPhone interface drove sales of the iPad, and will probably show up on future desktop computers.

Kinect is supposed to be just an input device to a gaming system. Instead, Kinect just might become another interface revolution, a new application platform and Microsoft's probably successful attempt to invent the future. The Kinect interface will probably become part of the PC interface of the future.

Kinect appears superficially to be nothing more than a Wii-like motion capture system. But it's way more than that.

It's a system that combines motion and gestures with voice recognition, face recognition and "environment," or a computer-generated space -- games, video, virtual worlds. It does all this in a very inexpensive, very accurate way that brings a long list of science-fiction like applications to the masses.

More important, it uses real cameras to capture motion, rather than laser, infra-red or other systems that don't enable photo and video applications.

Out of the box, Kinect realizes a "technology of the future" from our childhoods: The George Jetson video phone. Microsoft's Video Kinect app enables people to have video calls with family and friends. Of course, other video chat systems have existed for years. But Kinect is the first giant-screen system that's deployed already in millions of homes. While nobody was paying attention, giant-screen, Jetson-like video calls have gone mainstream.

Kinect also has the potential to usher in other "technologies of the future," including the gesture interface from "Minority Report," deeply immersive virtual reality a la "The Matrix," or "Star Trek," and other technologies that we're familiar with from science fiction.

The Future of Kinect

Ballmer introduced at CES something called Avatar Kinect, a virtual chat environment where your body movements, voice, hand gestures and even facial expressions are captured and applied to a cartoon version of you. Let's say three friends want to chat. They each launched the Avatar Kinect application, which shows all their avatars in a virtual environment on their TVs. Then, they just have a conversation. As they do so, their avatars interact with all movements and expressions on the TV.

Avatar Kinect appears to be a vastly superior version of the avatar-based chat idea that Google tried and failed with when it launched, then cancelled, Google Lively. With Lively, avatars were disconnected from users.

But with Avatar Kinect, the avatars mimic everything the user actually does. It's also got hooks into Facebook, apparently enabling chat sessions to take place inside the social network.

Microsoft also announced that Netflix and Hulu will be controllable with hand movements. The new feature will cost extra on the Xbox Live account. One subscribed, users will be able to navigate and control the movie and TV services with voice command and gestures.

Nice. But the real potential of Kinect is being demonstrated by others.

Researchers from the Technical University of Munich in Germany, for example, used Kinect to build a "virtual X-ray" prototype. The system takes CT scan images and uses them to simulate the experience of looking at a "magic mirror" that shows you your bones, organs and other innards.

A Kinect-based "magic mirror" that lets you try on virtual clothes in your own home while shopping online is nothing less than inevitable, and could eliminate the need for clothing stores.

Other developers have turned Kinect into a motion-capture machine. One even demonstrated the control of a humanoid robot in real-time. Obvious applications for this would be low-budget Hollywood movies, military bomb-disposal and infectious disease management.

A researcher at UC Davis has cobbled together a system for 3D video chat, where you can videoconference with a holographic 3D version of the person. It enables video chatters to be in the same virtual space, look at other in the eyes and even get up and look at the person from different angles.

The prototype is a very rough, very low-resolution version of the Star Trek "Holodeck." While prototype virtual reality systems have been demonstrated for decades, this is the first one already deployed in millions of living rooms.

Another pair of programmers created a "virtual piano" that can be projected onto any surface and played with hands and even feed by touching the desk or floor. The system is amazing because Microsoft hasn't yet optimized Kinect for finger gestures, which they have promised to do.

The list of innovations being developed for Kinect is very long and getting longer. The essential fact is that Kinect is breathtaking in its potential, and could transform how we interact with computers, including PCs.

A Brussels joint-venture called Softkinetic-Optrima showed at CES a gesture control system for TV. By waving hands and moving fingers, TV viewers can open menus, click on things, change the channel and turn up the volume, essentially replacing a TV remote. Softkinetic's technology works on both Windows and Linux.

The technology behind the TV controller is totally different from Kinect's. But someone -- probably Microsoft itself -- will very likely enable TV control with Kinect. They've already announced control of Netflix and Hulu. It's just a matter of time before they make the entire TV-watching experience gesture controlled.

Now that Kinect has been on the market for two months, it's becoming clear that Microsoft has really hit this one out of the park. Kinect is truly revolutionary, and has the potential to transform human culture. It's the little product that could change the world. Kinect is Microsoft's iPhone.